1. Field of the Invention
The present invention relates generally to visual inspection equipment and, more particularly, to a high-temperature inspection device employing a cooling apparatus, which enables continuous inspecting operations within high-temperature environments for extended periods of time. The invention also relates to cooling apparatus for high-temperature inspection devices.
2. Background Information
Inaccessible or confined areas such as, for example, the internal parts of power industry components (e.g., without limitation, combustors; compressors; turbines; power generation tubes), often require routine inspection to maintain safe operating conditions, to detect a potential problem before it develops into a dangerous condition and to search for and pinpoint the source of an existing problem, such as, for example, lodged debris or a malfunctioning or broken component such as a turbine blade or vane, in order that necessary repairs can be promptly made.
Visual inspection devices such as, for example, electronic or video borescopes are typically used to visually inspect such otherwise inaccessible areas. For example, in order to avoid partial or complete disassembly of the structure of a combustion or steam turbine to conduct a routine or maintenance inspection, a video borescope may be inserted through an inspection port in the turbine, in order to enable the visual observation of the condition of internal parts.
An example of a typical industrial borescope apparatus is disclosed in U.S. Pat. No. 5,096,292. As shown in FIG. 1, such apparatus typically include an electronic borescope 2 and an image processing system 12. The electronic borescope 2 includes an operating section 4 and an elongated insertion section 6 having a flexible tube portion 8 extending therefrom. An optical system, such as, for example, an articulating video system 10 is attached to the distal end of the flexible tube portion 8 and connected to the image processing system 12 by electronic cable 14. The operating section 4 includes a controlling mechanism 16 for adjusting the articulating video system 10, in order to conduct a visual inspection. A compressor 18 and an air hose 20 may optionally be used to supply compressed air to a jet port 22, in order to move or stabilize the elongated insertion section 6.
Such prior art electronic borescope systems and the video inspection equipment associated therewith cannot withstand high temperatures. Accordingly, until now, when internal combustion turbine components needed to be visually inspected or monitored, it was necessary to first cool the turbine to a temperature below approximately 150° F. (66° C.) before inserting the borescope to begin the inspection. This is an expensive and time-consuming process. For example, approximately 12 to 24 hours of cooling time are required to shut down and cool the combustion turbine from its operating temperature of approximately 800° F. (427° C.), to a temperature below approximately 150° F. (66° C.), at which video inspection equipment can withstand continuous inspection operations for extended periods of time. Upwards of approximately 120 hours may be necessary to shut down and cool a steam turbine.
There is a need therefore, for a high-temperature visual inspection system capable of operating continuously within high-temperature environments for extended periods of time.
Accordingly, there is room for improvement in cooling apparatus for visual inspection equipment and in visual inspection equipment employing cooling apparatus.